Cu and Mn centered nicotinamide/nicotinic acid complexes for interlayer of Schottky photodiode

Kocyigit Adem,Yıldız Dilber Esra,Hussaini Ali Akbar,Kose Dursun Ali,Yıldırım Murat 한국물리학회 2023 Current Applied Physics Vol.45 No.-

Schottky type photodiodes have gained great interest due to their fast response to light. Various materials have been used to improve their efficiency behaviors as interlayers or electrodes. In this study, we synthesized Cu- and Mn-centered nicotinamide/nicotinic acid complexes and used them for Schottky type photodiode as interfacial layer. Thus, Al/Cu-complex/p-Si and Al/Mn-complex/p-Si metal semiconductor heterojunctions were fabricated by Al metal and p-Si semiconductor. The I–V and I-t analyses were employed to identify the fabricated devices under various light power intensities. The devices were evaluated according to various diode parameters such as series resistance, ideality factor and barrier height values obtained by I–V characteristics data from thermionic emission theory, Cheung and Norde techniques. Furthermore, various parameters of photodetection such as specific detectivity, photosensitivity and responsivity were calculated from the I-t measurements. The results reveal that heterojunctions can be employed for photodiode applications.

The effect of COVID-19 pandemic on university education: Adoption of e-learning and testing the technology acceptance model

Bahar Akın,Hasan Boztoprak,Yıldız Yılmaz Guzey,Murat Süslü 한국교육개발원 2022 KEDI Journal of Educational Policy Vol.19 No.2

This study aims to investigate the factors affecting the acceptance of e-learning among university students, especially during the COVID-19 pandemic, and to reveal the factors affecting the reasons for students to use e-learning systems. We adopted the Technology Acceptance Model (TAM) to understand better the adoption of e-learning systems by university students. We gathered data from 716 university students who received distance education during the pandemic and used SPSS 22.0, AMOS 22.0 and SmartPLS 3.3 software to perform statistical analyses. The findings indicate that compatibility is related to perceived ease of use and perceived usefulness. Moreover, attitude is influenced by perceived ease of use and perceived usefulness. The results reveal the importance of perceived ease of use, perceived usefulness, self-learning necessity, and compatibility on intention to use.

Apelin Levels In Isolated Coronary Artery Ectasia

Mehmet Zihni Bilik,İbrahim Kaplan,Abdulkadir Yıldız,Mehmet Ata Akıl,Halit Acet,Murat Yüksel,Nihat Polat,Mesut Aydın,Mustafa Oylumlu,Faruk Ertaș,Hasan Kaya,Sait Alan 대한심장학회 2015 Korean Circulation Journal Vol.45 No.5

Background and Objectives: The etiopathogenesis of coronary artery ectasia (CAE) is not known completely. In most of the cases, CAE is associated with atherosclerosis; however, isolated CAE has a nonatherosclerotic mechanism. The association between atherosclerotic coronary artery disease and apelin has been examined in previous studies. However, the role of plasma apelin in isolated coronary artery ectasia has not been studied. In this study, we investigated the relationship between plasma apelin levels and isolated coronary artery ectasia. Subjects and Methods: The study population included a total of 54 patients. Twenty-six patients had isolated CAE (53.6±8.1 years); 28 patients with normal coronary arteries (51.6±8.8 years) and with similar risk factors and demographic characteristics served as the control group. Apelin levels were measured using an enzyme-linked immunoassay kit. Results: Apelin level in the CAE group was significantly lower (apelin=0.181±0.159 ng/mL) than that in the control group (apelin=0.646±0.578 ng/mL) (p=0.033). Glucose, creatinine, total cholesterol, triglyceride, low density lipoprotein cholesterol, and high density lipoprotein cholesterol levels were not significantly different between the two groups. Conclusion: In this study, we showed that patients with isolated CAE have decreased plasma apelin levels compared with the control group. Based on the data, a relationship between plasma apelin and isolated CAE was determined.

Predictive factors affecting morcellation efficiency in holmium laser enucleation of the prostate

Hakan Anıl,Ahmet Güzel,Ali Yıldız,Serkan Akdemir,Kaan Karamık,Murat Arslan 대한비뇨의학회 2023 Investigative and Clinical Urology Vol.64 No.4

Purpose: To determine the factors affecting morcellation efficiency in holmium laser enucleation of the prostate (HoLEP) surgery. Materials and Methods: Patients who underwent HoLEP surgery by a single surgeon between 2018 and 2022 were included in the study. Our primary outcome of interest in this study was morcellation efficiency. The effect of preoperative and perioperative variables on morcellation efficiency was evaluated with linear regression analysis. Results: A total of 410 patients were included in the study. The mean morcellation efficiency was 6.95±1.70 g/min. Univariable and multivariable linear regression analysis was performed to identify factors affecting morcellation efficiency. Presence of the “beach ball” effect (small, round prostatic tissue fragments that are fibrotic and difficult to morcellate), the learning curve, resectoscope sheath type, prostate-specific antigen (PSA) density, morcellated tissue weight, and the presence of prostate calcification were found to be independent predictive factors (β=-1.107, 95% CI: -1.59 to -0.55, p<0.001; β=-0.514, 95% CI: -0.85 to -0.17, p=0.003; β=-0.394, 95% CI: -0.65 to -0.13, p=0.003; β=-0.302, 95% CI: -0.59 to -0.09, p=0.043; β=0.062, 95% CI: 0.05 to 0.06, p<0.001; β=-0.329, 95% CI: -0.55 to -0.10, p=0.004; respectively). Conclusions: This study reports that presence of the beach ball effect, the learning curve, small resectoscope sheath, PSA density, and presence of prostate calcification negatively affect morcellation efficiency. On the contrary, morcellated tissue weight has a linear relationship with morcellation efficiency.

A novel method for high-frequency transgenic shoot regeneration via Agrobacterium tumefaciens in flax (Linum usitatissimum L.)

Ramazan Beyaz,E. Selcen Darçın,Murat Aycan,Mustafa Kayan,Mustafa Yıldız 한국식물생명공학회 2016 JOURNAL OF PLANT BIOTECHNOLOGY Vol.43 No.2

In this study, routinely used transformation method, which includes transferring explants onto co-cultivation medium after inoculating them with bacterial solution for a while, was compared with 3 different inoculation methods. In every 3 methods, hypocotyl explants excised from 7-day-old sterile flax seedlings having cotyledon leaves and no root system dried under air flow in sterile cabin for 35 min were inoculated with different volumes of bacterial solution at different inoculation periods. GV2260 line of Agrobacterium tumefaciens having ‘pBIN 19’ plasmid containing npt II (neomycin phosphotransferase II) gene and GUS reporter gene was used in transformation studies. After inoculation, hypocotyl segments of seedlings (0.5 cm in length) - were excised and left to co-cultivation for 2 days. Then, explants were transferred to regeneration medium supplemented with different antibiotics. The presence of npt-II and GUS genes in transformants was confirmed by PCR and GUS analysis. The highest results in all characters examined in all cultivars were obtained from the 2 inoculation method in which hypocotyls excised from seedlings inoculated with 500 μl of bacterial solution after drying in sterile cabin for 35 min were used.

Properties and Corrosion Resistance of AISI H13 Hot-Work Tool Steel with Borided B4C Powders

Ali Günen,İsmail Hakki Karahan,Mustafa Serdar Karakaş,Bülent Kurt,Yusuf Kanca,Vedat Veli Çay,Murat Yıldız 대한금속·재료학회 2020 METALS AND MATERIALS International Vol.26 No.9

In this study, the surface of AISI H13 steel was borided with powder blends of B4Cand NaBF4using the powder-pack methodat 800, 900 and 1000 °C for 2, 4 and 6 h. The structural and mechanical characteristics of the boride layers formed on thesurface were characterized using scanning electron microscopy, energy dispersive spectroscopy, X-ray diffractometry, 2Dsurface profilometry, microhardness and electrochemical corrosion (3.5 wt% NaCl) tests. The boride layer exhibited a singlephase structure (Fe2B) in samples coated at 800 °C and a dual-phase structure (FeB + Fe2B) at higher boriding temperatures(900 and 1000 °C). The boride layers were compact and crack-free in all boriding conditions. Depending on boridingparameters, the thickness, hardness and average surface roughness (Ra) of the coatings were found to range between 5.81and 102.46 μm, 1635–1915 HV and 0.315–0.650 μm, respectively. The borided AISI H13 steel displayed up to 33.5 timesand 2.4 times higher corrosion resistance than untreated AISI H13 steel and martensitic AISI 431 steel, respectively. Thissuggests potential use of borided AISI H13 steel in the steam turbines and marine applications as an alternative to the morecostly martensitic and duplex stainless steel grades. The corrosion resistance depended on the phase structure (single- ordual-layer), density, thickness and surface roughness of the boride coatings.